In a large pot, heat olive oil over medium heat.
Add the Italian sausage and cook until browned, breaking it into pieces.
Remove the sausage and set aside, leaving the fat in the pot.
Sauté the diced onion in the same pot until translucent.
Add minced garlic and sauté for another minute.
Pour in the chicken broth and bring to a boil.
Add the diced potatoes and cook until tender, about 10 minutes.
Stir in the cooked sausage and chopped kale.
Reduce heat and mix in the heavy cream.
Season with salt, pepper, and red pepper flakes before serving.